Semiconductor devices

ABSTRACT

Semiconductor devices may include a diffusion prevention insulation pattern, a plurality of conductive patterns, a barrier layer, and an insulating interlayer. The diffusion prevention insulation pattern may be formed on a substrate, and may include a plurality of protrusions protruding upwardly therefrom. Each of the conductive patterns may be formed on each of the protrusions of the diffusion prevention insulation pattern, and may have a sidewall inclined by an angle in a range of about 80 degrees to about 135 degrees to a top surface of the substrate. The barrier layer may cover a top surface and the sidewall of each if the conductive patterns. The insulating interlayer may be formed on the diffusion prevention insulation pattern and the barrier layer, and may have an air gap between neighboring ones of the conductive patterns.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/059,438, filed Mar. 3, 2016, which itself claims priority under 35U.S.C §119 to Korean Patent Application No. 10-2015-0050024, filed onApr. 9, 2015 in the Korean Intellectual Property Office (KIPO), thedisclosures of both of which are herein incorporated by reference intheir entireties.

BACKGROUND 1. Field

Example embodiments relate to a semiconductor device. More particularly,example embodiments relate to a semiconductor device having a wiringstructure.

2. Description of the Related Art

Recently, as the integration degree of a semiconductor device increases,a line width and a pitch of wiring patterns in the semiconductor devicehave decreased. Accordingly, a parasitic capacitance between theneighboring wiring patterns may increase thereby to cause RC delay and areduction of an operational speed of the semiconductor device.

SUMMARY

Example embodiments provide a semiconductor device having a reducedparasitic capacitance.

According to example embodiments, a semiconductor device includes adiffusion prevention insulation pattern, a plurality of conductivepatterns, a barrier layer, and an insulating interlayer. The diffusionprevention insulation pattern may have a plurality of protrusionsprotruding upwardly therefrom. Each of the conductive patterns may beformed on each of the protrusions of the diffusion prevention insulationpattern, and may have a sidewall inclined by an angle in a range ofabout 80 degrees to about 135 degrees to a top surface of the substrate.The barrier layer may cover a top surface and the sidewall of each ofthe conductive patterns. The insulating interlayer may be formed on thediffusion prevention insulation pattern and the barrier layer, and mayhave an air gap between neighboring ones of the conductive patterns.

In example embodiments, a width of a top surface of each of theconductive patterns may be smaller than that of a bottom surfacethereof.

In example embodiments, a width of a top surface of each of theconductive patterns may be greater than that of a bottom surfacethereof.

In example embodiments, a top surface of each of the conductive patternsmay be a curve that is convex upwardly.

In example embodiments, a lower sidewall of each of the conductivepatterns may be inclined by an angle in a range of about 90 degrees toabout 135 degrees to the top surface of the substrate, and an uppersidewall of each of the conductive patterns may be inclined by an anglein a range of about 80 degrees to about 90 degrees to the top surface ofthe substrate.

In example embodiments, the conductive patterns may include a metal,e.g., copper, aluminum, tungsten, nickel, or the like.

In example embodiments, the barrier layer may include a metal, e.g.,tantalum, cobalt, aluminum, manganese, or the like, or a nitride thereof

In example embodiments, the barrier layer may include graphene.

In example embodiments, the barrier layer may cover an upper surface ofa portion of the diffusion prevention insulation pattern between theneighboring ones of the conductive patterns.

In example embodiments, the insulating interlayer may include siliconcarbonitride.

In example embodiments, the diffusion prevention insulation pattern mayinclude silicon nitride, silicon carbonitride, silicon carbide, and/orsilicon oxynitride.

According to example embodiments, a semiconductor device includes adiffusion prevention insulation pattern, a plurality of conductivepatterns, a catalyst pattern, a gap formation inducing layer, a barrierlayer, and an insulating interlayer. The diffusion prevention insulationpattern may be formed on a substrate, and may have a plurality ofprotrusions protruding upwardly therefrom. Each of the conductivepatterns may be formed on each of the protrusions of the diffusionprevention insulation pattern. The catalyst pattern may be formed oneach of the conductive patterns. The gap formation inducing layer may beformed on the catalyst pattern, and may have a width greater than thatof the catalyst pattern. The barrier layer may cover sidewalls of theconductive patterns and the catalyst patterns, an upper surface of aportion of the diffusion prevention insulation pattern betweenneighboring ones of the conductive patterns, and the gap formationinducing layers. The insulating interlayer may be formed on the barrierlayer, and may have an air gap between the neighboring ones of theconductive patterns.

In example embodiments, the catalyst pattern may include a metal, e.g.,cobalt, nickel, tantalum, manganese, or the like.

In example embodiments, the gap formation inducing layer may include ametal nitride, e.g., aluminum nitride, or graphene.

In example embodiments, each of the conductive patterns may have asidewall inclined by an angle in a range of about 80 degrees to about135 degrees to a top surface of the substrate.

According to example embodiments, a semiconductor device includes asubstrate having an active fin defined by an isolation layer, a gatestructure formed on the active fin, a source/drain layer formed on theactive fin adjacent to the gate structure, a first insulating interlayerformed on the substrate and covering the gate structure, a diffusionprevention insulation pattern formed on the first insulating interlayerand having a plurality of protrusions protruding upwardly therefrom, aplurality of conductive patterns formed on the protrusions of thediffusion prevention insulation pattern, respectively, and having asidewall inclined by a given slope, a barrier layer covering a topsurface and the sidewall of each of the conductive patterns, and asecond insulating interlayer formed on the diffusion preventioninsulation pattern and the barrier layer and having an air gap betweenneighboring ones of the conductive patterns.

In example embodiments, the conductive pattern may include a metal,e.g., copper, aluminum, tungsten, nickel, or the like. The barrier layermay include a metal, e.g., tantalum, cobalt, manganese, or the like, ora nitride thereof.

In example embodiments, the second insulating interlayer may includesilicon carbonitride, and the diffusion prevention insulation patternmay include silicon nitride, silicon carbonitride, silicon carbide, orsilicon oxynitride.

In example embodiments, the gate structure may include a gate insulationlayer pattern and a gate electrode sequentially stacked on the activefin. The gate insulation layer pattern may include a metal oxide havinga high dielectric constant, and the gate electrode may include a metal.

In example embodiments, the source/drain layer may include an epitaxiallayer including silicon, silicon carbide, or silicon-germanium.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings. FIGS. 1 to 17 represent non-limiting, example embodiments asdescribed herein.

FIGS. 1 to 5 are cross-sectional views illustrating semiconductordevices, respectively, in accordance with example embodiments;

FIGS. 6 to 10 are cross-sectional views illustrating a method ofmanufacturing the semiconductor device in FIG. 1 in accordance withexample embodiments;

FIGS. 11 and 12 are cross-sectional views illustrating semiconductordevices, respectively, in accordance with example embodiments;

FIGS. 13 to 16 are cross-sectional views illustrating a method ofmanufacturing the semiconductor device in FIG. 11 in accordance withexample embodiments; and

FIG. 17 is a cross-sectional view illustrating a semiconductor device inaccordance with example embodiments.

DESCRIPTION OF EMBODIMENTS

Various example embodiments will be described more fully hereinafterwith reference to the accompanying drawings, in which some exampleembodiments are shown. The present inventive concept may, however, beembodied in many different forms and should not be construed as limitedto the example embodiments set forth herein. Rather, these exampleembodiments are provided so that this description will be thorough andcomplete, and will fully convey the scope of the present inventiveconcept to those skilled in the art. In the drawings, the sizes andrelative sizes of layers and regions may be exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numerals refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third,fourth etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present inventive concept.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting of thepresent inventive concept. As used herein, the singular forms “a,” “an”and “the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will be further understood thatthe terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, steps, operations,elements, components, and/or groups thereof.

Example embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized example embodiments (and intermediate structures). As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, example embodiments should not be construed as limitedto the particular shapes of regions illustrated herein but are toinclude deviations in shapes that result, for example, frommanufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the figures are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to limit the scope ofthe present inventive concept.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this inventive concept belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

FIGS. 1 to 5 are cross-sectional views illustrating semiconductordevices according to some example embodiments.

Referring to FIGS. 1 to 5, the semiconductor device may include a firstinsulating interlayer 110 on a substrate 100, a diffusion preventioninsulation pattern 122 on the first insulating interlayer 110, aplurality of conductive patterns 132 on protrusions 124 of the diffusionprevention insulation pattern 122, a barrier layer 140 covering a topsurface and a sidewall of each conductive pattern 132, and a secondinsulating interlayer 150 on the diffusion prevention insulation pattern122 and the barrier layer 140.

The substrate 100 may include a semiconductor material, e.g., silicon,germanium, silicon-germanium, or the like. In some example embodiments,the substrate 100 may include III-V compound semiconductor, e.g., GaP,GaAs, GaSb, or the like. In some example embodiments, the substrate 100may include a silicon-on-insulator (SOI) substrate or agermanium-on-insulator (GOI) substrate.

In some example embodiments, the substrate 100 may further includeelements that are formed by a front end of line (FEOL) process thereon.The first insulating interlayer 110 may cover the elements. The firstinsulating interlayer 110 may include an insulating material, e.g.,silicon dioxide (SiO₂) or a low-k material.

The diffusion prevention insulation pattern 122 on the first insulatinginterlayer 110 may include a plurality of protrusions 124 protrudingupwardly therefrom. Top surfaces of the protrusions 124 may contactbottom surfaces of the conductive patterns 132, respectively, and maypossibly prevent metal components contained in the conductive patterns132 from diffusing toward the first insulating interlayer 110. Thediffusion prevention insulation pattern 122 may include, e.g., siliconnitride, silicon carbonitride, silicon carbide, silicon oxynitride, orthe like.

In some example embodiments, the plurality of conductive patterns 132may be arranged in a second direction. Each of the conductive patterns132 may extend on each of the protrusions 124 of the diffusionprevention insulation pattern 122 in a first direction substantiallyperpendicular to the second direction. The conductive patterns 132 mayinclude a metal, e.g., copper, aluminum, tungsten, nickel, or the like.In some example embodiments, the conductive pattern 132 may beelectrically connected to the substrate 100 by vias (not illustrated) orcontacts (not illustrated) passing through the first insulatinginterlayer 110.

In some example embodiments, each of the conductive patterns 132 mayhave a sidewall inclined by a first angle θ1 to a top surface of thesubstrate 100. For example, the first angle θ1 may be in a range ofabout 80 degrees to about 135 degrees. When the first angle θ1 is in arange of about 80 degrees to about 90 degrees, a width of a top surfaceof each of the conductive pattern 132 may be less than that of a bottomsurface thereof (Refer to FIG. 1). In some example embodiments, when thefirst angle θ1 is in a range of about 90 degrees to about 135 degrees, awidth of the top surface of each of the conductive patterns 132 may begreater than that of the bottom surface thereof (Refer to FIG. 2).

As shown in FIG. 3, the top surface of each of the conductive patterns132 may have a curved shape that is convex upwardly. In FIG. 3, a topsurface of the barrier layer 140 has a curved shape that is convexupwardly, but it is not be limited thereto. For example, the barrierlayer 140 may have a top surface substantially parallel to the topsurface of the substrate 100.

As shown in FIG. 4, each of the conductive patterns 132 may include asidewall having an undercut shape. In other words, a lower sidewall ofeach of the conductive patterns 132 may be inclined by a second angle θ2to the top surface of the substrate 100, and an upper sidewall of eachof the conductive patterns 132 may be inclined by a third angle θ3different from the second angle θ2 to the top surface of the substrate100. For example, the second angle θ2 may be in a range of about 90degrees to about 135 degrees and the third angle θ3 may be in a range ofabout 80 degrees to about 90 degrees. FIG. 4 shows that a length of thelower sidewall of each of the conductive patterns 132 is less than thatof the upper sidewall thereof, however, the shape of the sidewall ofeach of the conductive patterns 132 may not be limited thereto. In someexample embodiments, the length of the lower sidewall of each of theconductive patterns 132 may be equal to or greater than that of theupper sidewall thereof.

The barrier layer 140 on each of the conductive patterns 132 may extendin the first direction to cover the sidewall and the top surface of theconductive pattern 132. The barrier layer 140 may reduce or possiblyprevent the diffusion of metal components contained in the conductivepatterns 132 to the second insulating interlayer 150. The barrier layer140 may include a metal, e.g., tantalum, cobalt, aluminum, manganese, orthe like, a metal nitride, e.g., tantalum nitride, cobalt nitride,aluminum nitride, manganese nitride, or the like, or graphene.

In some example embodiments, the barrier layer 140 may cover a portionof the diffusion prevention insulation pattern 122 between neighboringones of the conductive patterns 132 in the second direction.

As shown in FIG. 5, the barrier layer 140 may cover the top surface andthe sidewall of the conductive pattern 132, and further extend in thesecond direction to cover a sidewall and an upper surface of thediffusion prevention insulation pattern 122. The neighboring ones of theconductive patterns 132 in the second direction may be connected to eachother by the barrier layer 140. In this case, the barrier layer 140 mayinclude an insulation material, e.g., silicon nitride, siliconcarbonitride, silicon carbide, silicon oxynitride, or the like, so thatthe conductive patterns 132 may be electrically insulated from eachother.

Referring back to FIG. 1, the second insulating interlayer 150 may beformed on the diffusion prevention insulation pattern 122 and thebarrier layer 140, and may cover the plurality of conductive patterns132. The second insulating interlayer 150 may include a plurality of airgaps 155 therein. Each of the air gaps 155 may be formed between theneighboring ones of the conductive patterns 132 in the second direction.Each of the air gaps 155 may have an air tunnel shape extending in thefirst direction. FIG. 1 shows that each of the air gaps 155 has atrapezoidal shape in which a width of a top is greater than that of abottom, however, the shape of the air gaps 155 may not be limitedthereto. For example, as shown in FIG. 4, a width of a middle portion ofeach of the air gaps 155 may be less than those of upper and lowerportions thereof.

The air gaps 155 may include air having a relatively low dielectricconstant. Accordingly, a parasitic capacitance between the neighboringones of the conductive patterns 132 adjacent to the air gap 155 may bereduced. It will be understood that “air gap” may be, for example, anyvoid or cavity, and may be a gap filled with air (e.g., an air-gap), agap filled with an inert gas or gases (e.g., an inert gas gap), a gapdefining a vacuum (e.g., a vacuum gap), etc.

In some example embodiments, the second insulating interlayer 150 mayinclude an oxide, e.g., silicon dioxide (SiO₂), or a low-k dielectricmaterial. In some example embodiments, the second insulating interlayer150 may include a material having a lower dielectric constant and ahigher elasticity than those of silicon dioxide (SiO₂) so as to form theair gaps 155. For example, the second insulating interlayer 150 mayinclude silicon carbonitride (SiCN).

As illustrated above, the semiconductor device may include theconductive patterns 132 each having the sidewall inclined by the anglein the range of about 80 degrees to about 135 degrees to the top surfaceof the substrate 100, the diffusion prevention insulation pattern 122having the plurality of protrusions 124 protruding upwardly, which maycontact the bottom surfaces of the conductive patterns 132, the barrierlayer 140 covering the top surface and the sidewall of each of theconductive patterns 132. Further, the semiconductor device may includethe air gaps 155 between the neighboring ones of the conductive patterns132. Accordingly, the parasitic capacitance of the semiconductor devicemay be reduced.

FIGS. 6 to 10 are cross-sectional views illustrating a method ofmanufacturing the semiconductor device in FIG. 1 in accordance withexample embodiments.

Referring to FIG. 6, a FEOL process may be performed to form elements(not illustrated) on a substrate 100. A first insulating interlayer 110may be formed on the substrate 100 to cover the elements. A diffusionprevention insulation layer 120 and a conductive layer 130 may besequentially formed on the first insulating interlayer 110.

Referring to FIG. 7, a mask structure 180 may be formed on theconductive pattern 130.

In some example embodiments, the mask structure 180 may include a hardmask 182 and a photoresist pattern 184 sequentially stacked. A hard masklayer (not illustrated) and a photoresist layer (not illustrated) may besequentially formed on the conductive layer 130, and exposure anddeveloping processes may be performed to form the mask structure 180. Insome example embodiments, a plurality of mask structures 180 may beformed on the conductive layer 130, which may be spaced apart from eachother by first openings 185.

In some example embodiments, the exposure process may be performedusing, e.g., chromium fluoride (KrF), argon fluoride (ArF), extremeultra violet (EUV), vacuum ultra violet (VUV), electron beam, X-ray, ionbeam, or the like.

The hard mask 182 may be formed of, e.g., carbon, a silicon-based spinon hard mask (SOH) material, a silicon oxynitride-based hard maskmaterial, or the like. In some example embodiments, the hard mask 182may not be formed, but the photoresist pattern 184 only may be formed.

Referring to FIG. 8, the conductive layer 130 may be etched to form aconductive pattern 132.

In some example embodiments, the conductive layer 130 may be etchedusing the mask structure 180 as an etching mask until a top surface ofthe diffusion prevention insulation layer 120 may be exposed.Accordingly, a plurality of conductive patterns 132 and second openings135 may be formed. A sidewall of the conductive pattern 132 may beinclined by an angle in a range of about 80 degrees to about 135 degreesto a top surface of the substrate 100. An upper portion of the diffusionprevention insulation layer 120 may be also partially etched to form adiffusion prevention insulation pattern 122 having a plurality ofprotrusions 124 at upper portions thereof.

Referring to FIG. 9, a barrier layer 140 may be formed on a top surfaceand the sidewall of the conductive pattern 132.

In some example embodiments, the barrier layer 140 may be formed on thetop surface and the sidewall of the conductive pattern 132 using amaterial that may be selectively deposited on the conductive pattern132. The barrier layer 140 may be formed of a metal, e.g., tantalum,cobalt, aluminum, manganese, or the like. In some example embodiments,the barrier layer 140 may be formed of a metal nitride, e.g., tantalumnitride, cobalt nitride, aluminum nitride, manganese nitride, or thelike, or graphene. The barrier layer 140 may be formed by, e.g., achemical vapor deposition (CVD) process.

In some example embodiments, the barrier layer 140 may be formed tofully cover an upper surface of a portion of the diffusion preventioninsulation pattern 122 between neighboring ones of the conductivepatterns 132 in the second direction. In this case, the barrier layer140 may be formed of a material substantially the same as or similar tothat of the diffusion prevention insulation pattern 122, e.g., siliconnitride, silicon carbonitride, silicon carbide, silicon oxynitride, orthe like.

Referring to FIG. 10, a plasma treatment may be performed on an uppersurface of the barrier layer 140.

In example embodiments, the plasma treatment may be performed using,e.g., nitrogen plasma, oxygen plasma, hydrogen plasma, mixed plasmaincluding nitrogen and hydrogen, tetrafluoromethane (CF4) plasma, and/orammonia plasma. The plasma treatment may be performed using a capacitivecoupled plasma (CCP) source or an inductively coupled plasma (ICP)source.

When the plasma treatment is performed, a fine film on the upper surfaceof the barrier layer 140 may be partially removed to form a fineconcavo-convex. Thus, the second insulating interlayer 150 may bedeposited on the upper surface of the barrier layer 140 better than onthe second openings between the neighboring ones of the conductivepatterns 132. Accordingly, an air gap 155 may be formed in each of thesecond openings 135.

Referring back to FIG. 1, a second insulating interlayer 150 may beformed on the diffusion prevention insulation pattern 122 and thebarrier layer 140.

In some example embodiments, the second insulating interlayer 150 may beformed under process conditions and using materials having relativelylow gap-filling properties. The second insulating interlayer 150 may beformed by, e.g., a plasma enhanced CVD (PECVD) process, a sputteringprocess, or the like.

Accordingly, the second insulating interlayer 150 may overhang atentrances of the second openings 135 by the conductive patterns 132.Thus, the second insulating interlayer 150 may not completely fill thesecond openings 135, and the air gap 155 may be formed between theneighboring ones of the conductive patterns 132.

The second insulating interlayer 150 may include a material having alower dielectric constant and a higher elasticity than those of silicondioxide (SiO₂). For example, the second insulating interlayer 150 may beformed of silicon carbonitride (SiCN).

As described above, in the method of manufacturing the semiconductordevice in accordance with example embodiments, the upper surface of thebarrier layer 140 may be cleaned by a plasma treatment, and/or thesecond insulating interlayer 150 having a low gap-filling property maybe formed. Accordingly, the air gaps 155 may be formed between theneighboring ones of the conductive patterns 132, and the parasiticcapacitance of the semiconductor device may be reduced.

FIGS. 11 and 12 are cross-sectional views illustrating semiconductordevices, respectively, in accordance with example embodiments. Thesemiconductor device in FIGS. 11 and 12 may be substantially the same asor similar to that illustrated with reference to FIG. 1 except for acatalyst pattern, a gap formation inducing layer, and a shape of abarrier layer. Thus, like reference numerals refer to like elements, anddetailed descriptions thereon may be omitted below in the interest ofbrevity.

Referring to FIGS. 11 and 12, the semiconductor device may include thefirst insulating interlayer 110 on the substrate 100, the diffusionprevention insulation layer 122 on the first insulating interlayer 110,the plurality of conductive patterns 132 on the protrusions 124 of thediffusion prevention insulation layer 122, respectively, a plurality ofcatalyst patterns 162 on the conductive patterns 132, respectively, agap formation inducing layer 170 on each of the catalyst patterns 162, abarrier layer 142 covering the conductive patterns 132, the catalystpatterns 162, the diffusion prevention insulation pattern 122 and thegap formation inducing layer 170, and the second insulating interlayer150 covering the barrier layer 142. The air gaps 155 may be formedbetween neighboring ones of the conductive patterns 132 in FIG. 11, andair gaps 145 may be formed between neighboring ones of the conductivepatterns 132 in FIG. 12.

Each of the catalyst patterns 162 may extend in the first direction oneach of the conductive patterns 132, which may be arranged in the seconddirection perpendicular to the first direction. The catalyst patterns162 may include a metal, e.g., cobalt, nickel, tantalum, manganese, orthe like.

In some example embodiments, each of the catalyst patterns 162 may fullycover a top surface of each of the conductive patterns 132. In someexample embodiments, each of the catalyst patterns 162 may partiallycover the top surface of each of the conductive patterns 132.

The gap formation inducing layer 170 may extend in the first directionon each of the catalyst patterns 162, which may be arranged in thesecond direction. The gap formation inducing layer 170 may include,e.g., aluminum nitride, graphene, or the like.

In some example embodiments, a width of the gap formation inducing layer170 may be greater than those of each of the catalyst patterns 162 andeach of the conductive patterns 132. Accordingly, a gap betweenneighboring ones of the gap formation inducing layers 170 may be smallerthan gaps between neighboring ones of the catalyst patterns 162 andbetween neighboring ones of the conductive patterns 132.

FIG. 11 shows that the gap formation inducing layer 170 has anelliptical-shaped cross-section, however, the shape of the gap formationinducing layer 170 may not be limited thereto. For example, a topsurface of the gap formation inducing layer 170 may be parallel to a topsurface of the substrate 100. In some example embodiments, the gapformation inducing layer 170 may have a rectangular-shapedcross-section.

The barrier layer 142 may cover sidewalls of the conductive patterns 132and the catalyst patterns 162, an upper surface of the diffusionprevention insulation layer 122, and the gap formation inducing layers170. The barrier layer 142 may reduce or possibly prevent the diffusionof metal component contained in the conductive patterns 132 to thesecond insulating interlayer 150. The barrier layer 142 may include,e.g., silicon nitride, silicon carbonitride, silicon carbide, siliconoxynitride, or the like.

As shown in FIG. 12, in some example embodiments, the barrier layer 142may extend in the first direction to cover top surfaces of the gapformation inducing layers 170. Accordingly, the air gap 145 may beformed between the neighboring ones of the conductive patterns 132 bythe barrier layer 142. FIG. 12 shows that the air gap 145 has adoor-shaped cross-section, however, the shape of the air gap 145 may notbe limited thereto, and the air gap 145 may have various shapes.

In this case, the second insulating interlayer 150 may be formed on thebarrier layer 142, and may include no air gap therein.

FIGS. 13 to 16 are cross-sectional views illustrating a method ofmanufacturing the semiconductor device in FIG. 11 in accordance withexample embodiments. The semiconductor device in FIGS. 13 to 16 may besubstantially the same as or similar to that illustrated with referenceto FIGS. 6 to 10 except for a catalyst pattern, a gap formation inducinglayer, and a shape of a barrier layer. Thus, like reference numeralsrefer to like elements, and detailed descriptions thereon may be omittedbelow in the interest of brevity.

First, processes substantially the same as or similar to thoseillustrated with reference to FIG. 6 may be performed, so that the firstinsulating interlayer 110, the diffusion prevention insulation layer120, and the conductive layer 130 sequentially stacked on the substrate100 may be formed.

Referring to FIG. 13, a catalyst layer 160 may be formed on theconductive layer 130.

In some example embodiments, the catalyst layer 160 may be formed of ametal, e.g., cobalt, nickel, tantalum, manganese, or the like.

Referring to FIG. 14, a process substantially the same as or similar tothat illustrated with reference to FIG. 7 may be performed, so that amask structure (not illustrated) may be formed on the catalyst layer160. The catalyst layer 160 and the conductive layer 130 may be etchedusing the mask structure as an etching mask to form a catalyst pattern162 and the conductive pattern 132, respectively. In some exampleembodiments, a plurality of catalyst patterns 162 and the plurality ofconductive patterns 132 may be formed. The second opening 135 may beformed between structures including the catalyst layer 160 and theconductive layer 130.

Similar to the process described with reference to FIG. 8, theconductive pattern 132 may be formed to have the sidewall inclined bythe angle in a range of about 80 degrees to about 135 degrees to the topsurface of the substrate 100. Accordingly, a top surface of thediffusion prevention insulation layer 120 may be partially removed toform the diffusion prevention insulation pattern 122 having theprotrusion 124 at upper portions thereof.

Referring to FIG. 15, a gap formation inducing layer 170 may be formedon the catalyst pattern 162.

In some example embodiments, a width of the gap formation inducing layer170 may be greater than those of the catalyst pattern 162 and theconductive pattern 132. Accordingly, a gap between neighboring ones ofthe gap formation inducing layers 170 may be less than gaps betweenneighboring ones of the catalyst patterns 162 and between neighboringones of the conductive patterns 132.

In some example embodiments, the gap formation inducing layer 170 may beformed using a material that may be deposited selectively only on ametal component of the catalyst pattern 162. For example, the gapformation inducing layer 170 may be formed using aluminum nitride orgraphene by a CVD process.

Referring to FIG. 16, a barrier layer 142 may be formed to coversidewalls of the conductive patterns 132 and the catalyst patterns 162,an upper surface of the diffusion prevention insulation pattern 122, andthe gap formation inducing layers 170.

The barrier layer 142 may be formed of, e.g., silicon nitride, siliconcarbonitride, silicon carbide, silicon oxynitride, or the like.

In some example embodiments, the barrier layer 142 may fully coverentrances of the second openings 135 to form air gaps 145 between theneighboring ones of the conductive patterns 132, which is illustrated inFIG. 12.

Referring again to FIG. 11, the second insulating interlayer 150 may beformed on the barrier layer 142.

In some example embodiments, the second insulating interlayer 150 may beformed under process conditions and using a material having relativelylow gap-filling properties. The second insulating interlayer 150 may beformed by, e.g., a PECVD process, a sputtering process, or the like.

Accordingly, the second insulating interlayer 150 may overhang atentrances of the second openings 135 by the gap formation inducinglayers 170. Accordingly, the second insulating interlayer 150 may notcompletely fill the second openings 135, and air gaps 155 may be formedbetween the neighboring ones of the conductive patterns 132.

The second insulating interlayer 150 may be formed of a material havinga lower dielectric constant and a higher elasticity than those ofsilicon dioxide (SiO₂). For example, the second insulating interlayer150 may be formed of silicon carbonitride (SiCN).

Alternatively, the second insulating interlayer 150 may not be formedunder the process conditions and using a material having relatively lowgap-filling properties. For example, the second insulating interlayer150 may be formed of typical silicon dioxide (SiO₂) or a low-k material.In this case, entrances of the second openings 135 may be narrowed bythe gap formation inducing layers 170, so that the air gaps 155 may beformed.

As illustrated above, in the method of manufacturing the semiconductordevice, the gap formation inducing layers 170 may be formed on theconductive pattern 132. A width of each of the gap formation inducinglayers 170 may be greater than that of each of the conductive patterns132. Accordingly, the air gaps 155 may be formed between the neighboringones of the conductive patterns 132, and the parasitic capacitance ofthe semiconductor device may be reduced.

FIG. 17 is a cross-sectional view illustrating a semiconductor device inaccordance with example embodiments. FIG. 17 shows that thesemiconductor device includes a fin-type field effect transistor(finFET), however, the semiconductor device may not be limited thereto.

Referring to FIG. 17, the semiconductor device may include the finFET ona substrate 200, and a plurality of conductive patterns 270 electricallyconnected to the finFET. A first region I may illustrate a partialcross-sectional view of the semiconductor device taken along a firstdirection, and a second region II may illustrate a partialcross-sectional view of the semiconductor device taken along a seconddirection substantially perpendicular to the first direction.

The substrate 200 may include a semiconductor material, e.g., silicon,germanium, silicon-germanium, or the like. In some example embodiments,the substrate 200 may include a III-V compound semiconductor, e.g., GaP,GaAs, GaSb, or the like. In some example embodiments, the substrate 200may include a SOI substrate or a GOI substrate.

The finFET may include a gate structure 210 and a source/drain layer206.

Particularly, the substrate 200 may include a field region where a topsurface is covered by an isolation layer 202, and an active region wherea top surface is not covered by the isolation layer 202. The activeregion may have a fin-like shape protruding upwardly from the substrate200. Thus, hereinafter, the active region having fin-like shape may bereferred to as an active fin 204.

In some example embodiments, a plurality of active fins 204 may bearranged in the first direction substantially parallel to a top surfaceof the substrate 200. Each of the active fins 204 may extend in thesecond direction parallel to the top surface of the substrate 200 andsubstantially perpendicular to the first direction.

The isolation layer 202 may include an oxide, e.g., silicon oxide.

A plurality of gate structures 210 may be arranged in the seconddirection. Each of the gate structure 210 may cover the active fin 204and extend in the first direction.

In some example embodiments, the gate structure 210 may include a gateinsulation layer pattern 212 and a gate electrode 214 sequentiallystacked on the active fin 204, and the isolation layer 202. The gatestructure 210 may further include an interface pattern (not illustrated)between the gate insulation layer pattern 212 and the active fins 204.

The gate insulation layer pattern 212 may include a metal oxide having ahigh dielectric constant that is higher than that of silicon oxide,e.g., hafnium dioxide (HfO₂), tantalum oxide (Ta2O5), zirconium oxide(ZrO₂), or the like. The gate electrode 214 may include a low resistancemetal, e.g., aluminum, copper, tantalum, or the like, or a nitridethereof.

A spacer 218 may cover a sidewall of the gate structure 210. The spacer218 may include a nitride, e.g., silicon nitride.

The source/drain layer 206 may be formed on the active fin 204 adjacentto the gate structure 210. The source/drain layer 206 may includeimpurities.

The source/drain layer 206 may include an epitaxial layer including,e.g., silicon, silicon carbide, silicon-germanium, or the like. Theepitaxial layer may be formed by a selective epitaxial growth (SEG)process using the top surface of the substrate 200 as a seed.

A third insulating interlayer 220 and a fourth insulating interlayer 240may be sequentially formed on the substrate 200. The third insulatinginterlayer 220 may cover the finFET. For example, the third and fourthinsulating interlayers 220 and 240 may include a silicon oxide.

In some example embodiments, the third and fourth insulating interlayers220 and 240 may include a lower contact plug 230 and an upper contactplug 252 therethrough, respectively. The lower contact plug 230 and theupper contact plug 252 may electrically connect the source/drain layer206 to the conductive pattern 270. A contact pad 250 may be formedbetween the lower contact plug 230 and the upper contact plug 252.

The lower contact plug 230 may penetrate through the third insulatinginterlayer 220, and may electrically connect the source/drain layer 206to the contact pad 250. The upper contact plug 252 may penetrate throughthe fourth insulating interlayer 240, and may electrically connect thecontact pad 250 to the conductive pattern 270.

A metal wiring may be formed on the fourth insulating interlayer 240 bya back end of line (BEOL) process. For example, the metal wiring mayinclude a fifth insulating interlayer 290 including a plurality ofconductive patterns 270, a diffusion prevention insulation pattern 262covering a bottom surface of each of the conductive patterns 270, abarrier layer 280 covering a top surface and a sidewall of each of theconductive patterns 270, and an air gap 295 between neighboring ones ofthe conductive patterns 270.

The diffusion prevention insulation pattern 262 may be formed on thefourth insulating interlayer 240, and may have a plurality ofprotrusions 264 protruding upwardly therefrom. Each of the protrusions264 may contact a bottom surface of each of the conductive patterns 270,and may reduce or possibly prevent the diffusion of metal componentscontained in the conductive patterns 270 to the fourth insulatinginterlayer 240. The diffusion prevention insulation pattern 262 mayinclude, e.g., silicon nitride, silicon carbonitride, silicon carbide,silicon oxynitride, or the like.

The plurality of conductive patterns 270 may be arranged in the seconddirection. Each of the conductive patterns 270 may extend on each of theprotrusions 264 of the diffusion prevention insulation pattern 262 inthe first direction. The conductive patterns 270 may include a metal,e.g., copper, aluminum, tungsten, nickel, or the like. The bottomsurface of each of the conductive patterns 270 may contact the uppercontact plug 252, and may be electrically connected to the source/drainlayer 206.

In example embodiments, each of the conductive patterns 270 may includea sidewall inclined by a given slope to the top surface of the substrate200. For example, the sidewall of each of the conductive patterns 270may be inclined by an angle in a range of about 80 degrees to about 135degrees to the top surface of the substrate 200.

In some example embodiments, a slope of a lower sidewall of each of theconductive patterns 270 may differ from that of an upper sidewallthereof. For example, the lower sidewall of each of the conductivepatterns 270 may be inclined by an angle in a range of about 90 degreesto about 135 degrees, while the upper sidewall of the conductive pattern270 may be inclined by an angle in a range of about 80 degrees to about90 degrees.

Further, the top surface of the conductive pattern 270 may not beparallel to the top surface of the substrate 200. For example, theconductive pattern 270 may have a curved top surface, which may beconvex upwardly.

The barrier layer 280 may cover the top surface and the sidewall of eachof the conductive patterns 270. The barrier layer 280 may reduce orpossibly prevent the diffusion of metal components contained in theconductive patterns 132 to the second insulating interlayer 150. Thebarrier layer 280 may include a metal, e.g., tantalum, cobalt, aluminum,manganese, or the like. Alternatively, the barrier layer 280 may includea metal nitride, e.g., tantalum nitride, cobalt nitride, aluminumnitride, manganese nitride, or the like, or graphene.

In some example embodiments, the barrier layer 280 may extend in thesecond direction to fully cover an upper surface of a portion of thediffusion prevention insulation pattern 262 between the neighboring onesof the conductive patterns 270. The barrier layer 280 may include amaterial substantially the same as that of the diffusion preventioninsulation pattern 262. For example, the barrier layer 280 may includesilicon nitride, silicon carbonitride, silicon carbide, siliconoxynitride, or the like.

The fifth insulating interlayer 290 may be formed on the diffusionprevention insulation pattern 262 and the barrier layer 280, and maycover the plurality of conductive patterns 270. The fifth insulatinginterlayer 290 may include a plurality of air gaps 295 therein. Each ofthe air gaps 295 may be formed between the neighboring ones of theconductive patterns 270. Each of the air gaps 295 may have an air tunnelshape extending in the first direction. The air gaps 295 may include airhaving a relatively low dielectric constant, and thus a parasiticcapacitance between the neighboring ones of the conductive patterns 270adjacent to the air gaps 295 may be reduced.

As illustrated above, the semiconductor device may include the air gaps295 between the neighboring ones of the conductive patterns 270.Accordingly, the parasitic capacitance of the semiconductor device maybe reduced.

The foregoing is illustrative of example embodiments and is not to beconstrued as limiting thereof. Although a few example embodiments havebeen described, those skilled in the art will readily appreciate thatmany modifications are possible in the example embodiments withoutmaterially departing from the novel teachings and advantages of thepresent inventive concept. Accordingly, all such modifications areintended to be included within the scope of the present inventiveconcept as defined in the claims. In the claims, means-plus-functionclauses are intended to cover the structures described herein asperforming the recited function and not only structural equivalents butalso equivalent structures. Therefore, it is to be understood that theforegoing is illustrative of various example embodiments and is not tobe construed as limited to the specific example embodiments disclosed,and that modifications to the disclosed example embodiments, as well asother example embodiments, are intended to be included within the scopeof the appended claims.

1. A semiconductor device, comprising: a diffusion prevention insulationpattern on a substrate, the diffusion prevention insulation patterncomprising a plurality of protrusions protruding upwardly therefrom; aplurality of conductive patterns on the plurality of protrusions of thediffusion prevention insulation pattern, respectively, each of theplurality of conductive patterns comprising a sidewall tapered in avertical direction; a barrier layer covering at least a top surface ofeach of the plurality of conductive patterns; and an insulatinginterlayer on the plurality of conductive patterns and the barrierlayer, wherein an air gap is disposed between neighboring ones of theplurality of conductive patterns.
 2. The semiconductor device of claim1, wherein a width of the top surface of each of the plurality ofconductive patterns is less than a width of a bottom surface thereof. 3.The semiconductor device of claim 1, wherein a width of the top surfaceof each of the plurality of conductive patterns is greater than a widthof a bottom surface thereof.
 4. The semiconductor device of claim 1,wherein each of the plurality of conductive patterns includes copper,aluminum, tungsten, and/or nickel.
 5. The semiconductor device of claim1, wherein the barrier layer includes tantalum, cobalt, aluminum,manganese, and/or a nitride thereof.
 6. The semiconductor device ofclaim 1, wherein the insulating interlayer includes siliconcarbonitride.
 7. The semiconductor device of claim 1, wherein thediffusion prevention insulation pattern includes silicon nitride,silicon carbonitride, silicon carbide, and/or silicon oxynitride.
 8. Asemiconductor device, comprising: a diffusion prevention insulationpattern on a substrate; a conductive pattern on the diffusion preventioninsulation pattern, the conductive pattern having a sidewall that is notsubstantially vertical to a top surface of the substrate; a barrierlayer on an upper surface of the conductive pattern; an insulatinginterlayer on the barrier layer and the conductive pattern; and an airgap in the insulating interlayer, the air gap horizontally overlappingat least a portion of the sidewall of the conductive pattern.
 9. Thesemiconductor device of claim 8, wherein a width of the upper surface ofthe conductive pattern is less than a width of a lower surface thereof.10. The semiconductor device of claim 8, wherein the conductive patternincludes a plurality of conductive patterns, and wherein the air gap isbetween neighboring ones of the plurality of conductive patterns.